| 摘要 |
In self-reversing tapping attachments improved ball drive means are connectable to source of rotational drive (12) and drive transmitting means (40) are engagable, with the drive means including at least one driving ball member (32,33) and with the drive transmitting means defining at least one slot (46,48) for the ball member, which slot includes a ramp section (50,52) inclined so that upon engagement between the drive means and the ball member the latter travels upwardly thereby cushioning impact between the drive means and the drive transmitting means. A radially extending member (66) on a tap holder member has a radius of curvature less than the radius of curvature of contact members of the drive transmitting means to cushion impact. <IMAGE> |
